Pedals with Shins, Float and Arch-ward?

I'm looking for a pedal/cleat/shoe combination that allows about 3/8" shimming under the left (to accomodate a leg length dicrepancy), a moderate degree of float and the ability to move the cleats behind the ball of the foot, toward the arch.

Speedplay Zero seems to fit the bill - any other combinations to consider?

I inner pronate on my left leg much more than I do on my right leg (knee injury from Judo years ago) and so have Look CX7 pedals so I can counteract that on my bikes.
You could try them or get some wedges from Lemond (or make your own - you would need to experiment though).
Good luck.